Retailers, financial services firms, and other kinds of companies want to become more agile in their branch strategies: be able to light up, move, and shut down branches quickly and easily. One sticking point has always been the branch network stack: deploying, configuring, managing, and retrieving the router, firewall, WAN optimizer, etc., as branches come and go. And everyone struggles with deploying new functionality at all their branches quickly: multi-year phased deployments are not unusual in larger networks.
Network as a Service (NaaS) has arisen as a solution: use a router in the branch to connect to a provider point of presence, usually over the Internet, with the rest of the WAN’s functionality delivered there.
In-net SD-WAN is an extension of the NaaS idea: SD-WAN—centralized, policy-based management of the WAN delivering the key functions of WAN virtualization and application-aware security, routing, and prioritization—delivered in the provider’s cloud across a curated middle mile.
In-net SD-WAN allows maximum service delivery with minimum customer premises equipment (CPE) because most functionality is delivered in the service provider cloud, anywhere from edge to core. We’ve discussed how the benefits of this kind of simplification to the stack. It offers a host of other benefits as well, based on the ability to dedicate resources to SD-WAN work as needed, and the ability to perform that work wherever it is most effective and economical. Some jobs will best be handled in carrier points of presence (their network edge), such as packet replication or dropping, or traffic compression. Others may be best executed in public clouds or the provider’s core, such as traffic and security analytics and intelligent route management.
Cloud Stack Benefits the Enterprise: Freedom and Agility
People want a lot out of their SD-WAN solution: routing, firewalling, and WAN optimization, for example. (Please see figure 1.)
Enterprises working with in-net SD-WAN are more free to use resource-intensive functions without feeling the limits of the hardware at each site. They are free to try new functions more frequently and to deploy them more broadly without needing to deploy additional or upgraded hardware. These facts can allow a much more exact fit between services needed and services used since there is no up-front investment needed to gain the ability to test an added function.
Enterprises are also able to deploy more rapidly. On trying new functions at select sites and deciding to proceed with broader deployment, IT can snap-deploy to the rest. On lighting up a new site, all standard services—as well as any needed uniquely at that site—can come online immediately, anywhere.
Cloud Stack Benefits: Security and Evolution
The provider, working with a software-defined service cloud, can spin up new service offerings in a fraction of the time required when functions depend on specialized hardware. The rapid evolution of services, as well as the addition of new ones, makes it easier for an enterprise to keep current and to get the benefits of great new ideas.
And, using elastic cloud resources for WAN security functions decreases the load on networks, and on data center security appliances. Packets that get dropped in the provider cloud for security reasons don’t consume any more branch or data center link capacity, or firewall capacity, or threaten enterprise resources. This reduces risk for the enterprise overall.
Getting to Zero
A true zero-footprint stack is not possible, of course. Functions like link load balancing and encryption have to happen on premises so there always has to be some CPE (however generic a white box it may be) on site. But the less that box has to do, and the more the heavy lifting can be handled elsewhere, the more the enterprise can take advantage of all these benefits in an in-net SD-WAN.